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Providing evidence to improve practice

Individual study: Propane exploders and Electronic Guards were ineffective at reducing deer damage in cornfields

Published source details

Gilsdorf J.M., Hygnstrom S.E., VerCauteren K.C., Blankenship E.E. & Engeman R.M. (2004) Propane exploders and Electronic Guards were ineffective at reducing deer damage in cornfields. Wildlife Society Bulletin, 32, 524-531


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use lights and sound to deter crop damage by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, paired sites, controlled study in 1999 of corn fields at two sites in Nebraska, USA (Gilsdorf et al. 2004) found that a device emitting lights and sound (Electronic Guard) did not reduce crop visits by white-tailed deer Odocoileus virginianus. The number of deer visits/km of field boundary did not differ between treatment fields protected by Electronic Guards (38–46/day) and unprotected control fields (40–56/day). Similarly, there was no difference between fields before devices operated (treatment fields: 24 visits/km/day; control fields: 21 visits/km/day) or after operations ceased (treatment fields: 47 visits/km/day; control field: 53 visits/km/day). Four groups of fields were studied at each of two sites. Fields were 0.5–2.5 km apart and separated by woodland. In each group, one field was protected by two Electronic Guard devices and one field was unguarded. Electronic Guards comprised a strobe light (60 flashes/minute) and siren (116 dB at 1 m). They operated at night, from when corn crops became susceptible to damage (13 July 1999 at one site and 25 July 1999 at the second site), for 18 days. Deer activity was assessed by counting tracks twice while devices operated, once during the two weeks before devices operated and once during the week after they operated.

(Summarised by Nick Littlewood)

Use loud noises to deter crop damage (e.g. banger sticks, drums, tins, iron sheets) by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, paired sites, controlled study in 1999 of corn fields at two sites in Nebraska, USA (Gilsdorf et al. 2004) found that loud noises from propane exploders did not reduce visits to crops by white-tailed deer Odocoileus virginianus. The number of deer visits/km of field boundary was similar in fields protected by propane exploders (31–36/day) and unprotected fields (40–56/day). Similarly, there were no significant difference between fields before devices operated (exploders: 17 visits/km/day; unprotected: 21 visits/km/day) or after (exploders: 37 visits/km/day; unprotected: 53 visits/km/day). Four groups of fields (0.5–2.5 km apart, separated by woodland) were studied at each of two sites. At each site, one field had propane exploders (two/field) and one was unguarded. Propane exploders fired at 15-minute intervals. They operated at night, from when corn crops became susceptible to damage (13 July 1999 at one site and 25 July 1999 at the second site), for 18 days. Deer activity was assessed by counting tracks twice while devices operated and once each in ≤2 weeks before and after this time.

(Summarised by Nick Littlewood)